<mat-tree [dataSource]="dataSource" [treeControl]="treeControl">
  <mat-tree-node *matTreeNodeDef="let node" matTreeNodePadding>
    <button matIconButton disabled></button>
    {{node.item}}
  </mat-tree-node>
  <mat-tree-node *matTreeNodeDef="let node; when: hasChild" matTreeNodePadding matTreeNodeToggle
                [cdkTreeNodeTypeaheadLabel]="node.item">
    <button matIconButton
            [attr.aria-label]="'Toggle ' + node.item" matTreeNodeToggle>
      <mat-icon class="mat-icon-rtl-mirror">
        {{treeControl.isExpanded(node) ? 'expand_more' : 'chevron_right'}}
      </mat-icon>
    </button>
    {{node.item}}
    @if (node.isLoading()) {
      <mat-progress-bar
          mode="indeterminate"
          class="example-tree-progress-bar"></mat-progress-bar>
    }
  </mat-tree-node>
</mat-tree>
